The invention relates to cabin structures for vehicles, such cabins as used in wheelchair-accessible and other transit bus cabins. To allow access by passengers in wheelchairs, and disabled, elderly, or other passengers who have difficulty with stairs, including for example passengers with wheeled baby carriages or wheeled carrying devices, buses are commonly designed with a lower front floor section.
Such floors may be made increasingly accessible when the bus stops by, for example, operating “kneeling” front suspension or lateral tipping suspension mechanisms to bring the floor adjacent the front and rear doors closer to the exterior curb elevation. Extendable ramps or lifts are also commonly used to enable wheeled access between external sidewalk surfaces and the lower, usually forward, floor of the bus cabin.
Such bus cabin floors often have front wheel wells and/or other structures projecting significantly into the cabin, with a central aisle extending axially along the bus between the front wheel wells in buses with lower floors. The rear section of the bus usually includes an upper floor section beneath which the engine and other operating equipment is installed. A foot step can be used to transition between the lower and upper floor sections. The upper floor section is generally not accessible to wheelchairs or other wheeled devices.
Due to the lower forward floor design, space for engine machinery, fuel tanks, and other bulky equipment within the bus is generally limited to beneath the rear upper floor. However, such available space may be inadequate for certain bus configurations.
The transition step between the lower and upper floor sections is generally perpendicular to the central aisle extending axially through the bus cabin. Wheelchairs, baby carriages and other wheeled devices may collide or otherwise interfere with the step and become difficult to redirect laterally out the rear doors. Typically, wheelchair passengers and those with wheeled devices such as baby carriages prefer to exit through the front doors due to difficulty in navigating out the rear doors. This impedes entry of passengers through the front doors and generally slows down transit service as a result.
Features that distinguish the present invention from the background art will be apparent from review of the disclosure, drawings and description of the invention presented below.